A consist includes one or more locomotives that are coupled together to produce motive power for a train of rail vehicles. The locomotives each include one or more engines, which combust fuel to produce mechanical power. The engine(s) of each locomotive can be supplied with liquid fuel (e.g., diesel fuel) from an onboard tank, gaseous fuel (e.g., natural gas) from a tender car, or a blend of the liquid and gaseous fuels. The mechanical power produced by the combustion process is directed through a generator and used to generate electricity. The electricity is then routed to traction motors of the locomotives, thereby generating torque that propels the train. The locomotives can be connected together at the front of the train or separated and located at different positions along the train. For example, the consist can be positioned at the front, middle, or end of the train. In some instances, more than one consist can be included within a single train. The locomotives in a consist can be oriented in a forward-facing (or “long hood”) direction or a backward-facing (or “short hood”) direction. In some consists, the locomotives include computer systems for maintaining operations of the locomotive. These computer systems are sometimes disposed on the long hood side of the locomotive.
Because the locomotives of a consist must cooperate to propel the train, communication between the locomotives can be important. Historically, this communication has been facilitated through the use of an MU (Multi-Unit) cable that extends along the length of the consist. An MU cable is comprised of many different wires, each capable of carrying a discrete signal used to regulate a different aspect of consist operation. For example, a lead locomotive generates current within a particular one of the wires to indicate a power level setting requested by the train operator. When this wire is energized, the engines of all trail locomotives are caused to operate at a specific throttle value. In another example, when one locomotive experiences a fault condition, another of the wires is energized to alert the other locomotives of the condition's existence.
Although acceptable in some applications, the information traditionally transmitted via the MU cable may be insufficient in other applications. For example, during the fault condition described above, it can be important to know a severity and/or cause of the fault condition so that an appropriate response to the fault condition can be implemented in an effective and efficient manner. Additionally, as consist configurations become more complex, for example during multi-unit blended fuel operations (i.e., operations where gaseous fuel from a tender car is simultaneously supplied to multiple locomotives and mixed with diesel fuel at different rates), control of the locomotives and/or the tender car may require a greater amount of cooperation and/or more complex communication than can be provided via the MU cable.
One attempt to address the above-described problems is disclosed in U.S. Patent Publication 2010/0241295 of Cooper et al. that published on Sep. 23, 2010 (“the '295 publication”). Specifically, the '295 publication discloses a consist having a lead locomotive and one or more trail locomotives connected to each other via an MU cable. Each locomotive includes a computer unit, which, along with the MU cable, forms an Ethernet network in the train. With this configuration, network data can be transmitted from the computer unit in the lead locomotive to the computer units in the trail locomotives. The network data includes data that is packaged in packet form as data packets and uniquely addressed to particular computer units. The network data can be vehicle sensor data indicative of vehicle health, commodity condition data, temperature data, weight data, and security data. The network data is transmitted orthogonal to conventional non-network (i.e., command) data that is already being transmitted on the MU cable.
While the consist of the '295 publication may have improved communication between locomotives, it may still be less than optimal. In particular, the topology of the trainline communication network of the '295 publication does not provide indirect communication between locomotives, which can lead to poor overall network performance in some cases.
The system of the present disclosure solves one or more of the problems set forth above and/or other problems with existing technologies.